Paving machine



June 23, 1936. JA 2,044,883

/ PAVING MACHINE Filed Sept; 5, 1933 4 Sheets-Sheet 1 [NVENTOR [am/WJae/r600 June 23, 1936. c. JACKSON PAVING MACHINE Filed Sept. 5, 1935 4Sheets-Sheet 2 C. JACKSON PAVING MACHINE June 23, 1936.

4 Shets-Sheet 3 Filed Sept. 5, 1933 INYENTOR Cww/fl M205? ATTORNEY 3June 23, 1936. c. JACKSON PAVING MACHINE ,Filed Sept. 5, 1933 4Sheets-Sheet 4 INVENTOR 60/70/7/ Y r 9 g? ATTORNEYS J E. z a

brill, I

III

Patented June 23, 1936 UNITED [S A PATENT OFFICE .23 Claims.

The main objects of this invention are:

First, to provide a method of laying cement bound macadam which ishighly eiiicient and produces a very uniform and superior bed or slab.

Second,to provide a method of bonding aggregate in situ which may bevery economically practiced.

Third, to provide a machine or apparatus for bonding aggregate in situwhich is of large capacity and very efiicient.

Fourth, to provide a machine for laying cement bound macadam forhighways and the like which is very simple and economical in structureand operation.

Objects pertaining to detailsand economies of my invention will appearfrom the description to follow. Theinvention is defined in the. claims.

A structure embodying the features of my invention is illustrated in theaccompanying drawings, inwhich: r

Fig. 1 is a plan view of my improved machine for laying cement boundmacadam or applying grout to'aggregate in situ.

Fig.2 is a fragmentary view illustrating my machineor apparatus inoperation, a tractor and the materials operated upon beingconventionally illustrated and the machine being. sectioned on line 22of Figs. 1 and 3.

Fig. 3 is a fragmentary view partially in section on line 3-3 of Fig. 1.

Fig.4 is a fragmentary plan view of one of the vibrating units.

Fig. 5 is a fragmentary view of a modified form or embodiment of myinvention in which means are provided for maintaining a uniform amountor head of grout within the hopper.

Fig. 6 is a fragmentary view of another form or I embodiment of myinvention in which the screed.

is reciprocated as well as vibrated.

In the embodiment of my invention illustrated in Figs. 1 to 3 inclusive,I represents'a bed of crushed rock aggregate and '2 a portion thereofafter the cement grout has beendelivered thereto and worked throughoutthe aggregate, the grout being indicated at 3/ The machine is .propelledacross-thebedof aggregate by a tractoror power vehicle conventionallyillustrated at 4. 1

My improvements as illustrated in the embodiment of Figs. 1,. 2, and 3comprises ,a pair of screeds designated generallybyrthe numerals 5 and 6disposed in spaced parallel trai in rela-; tion. These screed units maybe substantial du plicates, as illustrated, arranged in reversedrelationand'comprise the transverse ,frame members I, 8, and 9 disposed inspaced relation and having shoes I 0 of plate or heavy sheet metalsecured thereto. The rivets or securing means are not illustrated.

These shoes have curved upturned outer edges H and curved upturned inneredges l2, the upturned inner edges being extended into upwardlydiverging hopper walls I3. The upturned curved forward edge I l of theforward screed constitutes an upwardly curved nose for the forwardscreed, while the upturned inner edge of the trailing or rear screedconstitutes an upwardly curved nose for the rear screed. These upwardlycurved inner edges provide a discharge opening M for the hopper I5. Thedischarge opening or throat has downwardly diverging walls which permitthe grout to be spread and flow into the aggregate as it is dischargedfrom the hopper.

A gate or valve I6 is supported centrally above the discharge of thehopper, this gate being preferably of V cross section as illustrated andsupported by the rods l1 rotatably secured to the gate, the connectionnot being detailed. These rods have threaded connection with thebrackets l0 carried by the connecting cross pieces IQ for the screeds.The connecting cross pieces are secured at theirends to the transverseframe members of the screeds and provide a rigid connection for thescreeds to the shoes of the screeds in the same plane. r

Each screed is provided with one or more vibrating units designatedgenerally by the numeral .20. A pair of vibrating units is provided bothin the aggregate before the grout is introduced andto the grout and tothe aggregateand grout, after the groutis introduced. .By the use of myapparatus, grout of low water content maybe successfully placed andworked throughout or thoroughly incorporated with the aggregate, .itbeing possible to successfully place.

grout \of three inch slump, whereas the present methodsof working thegrout into the rock by steam roller, for example, requires a slump offully. eleven inches which is a very thin flowing flowinggrout: that is,grout too thick to fill the mixture: I am enabled to successfully placenon; A

The vibrating hopper serves to effectively change the condition of thegrout from a non-flowing to a fluid condition and it is caused to flowuniformly through the hopper discharge.

The first screed, setting up vibrations in the aggregate, acts tocompact and settle the same into place; that is, reduces the voidstherein. It also brings the surface to an approximately level conditionand to a very substantial extent moves the aggregate to eliminate sharpprojecting edges. The grout is introduced and, as stated, subjected tovibrations, and the aggregate is subjected to vibrations as the grout isintroduced thereto, so substantially all voids are eliminated and thegrout worked throughout the bed.

The forward screed is provided with draw bars 24 attache-d to the screedframe members 8 and provided with a coupling 25.

While highly satisfactory results may be obtained by the apparatus shownin Figs. 1, 2, and 3, more uniform results may be obtained when aconstant head of grout is maintained within the hopper and in Fig. 5, Iillustrate an embodiment of my invention accomplishing this end. In thisembodiment, a grout mixer shown conventionally at 26 is mounted upon thetractor 4, this embodiment consisting of a pair of units designatedgenerally by the numerals 2! and 28 disposed in tandem relation, thefront unit 2'! being connected to the trailer by the draw bar 29 whilethe rear or trailing unit 28 is connected to the unit 21 by the draw bar30. These units, which are substantial duplicates, comprise a screed 3|provided with a vibrating unit or units 32. A curved screed or shoe 33is arranged in advance of the screed 3|, these screeds being rigidlyconnected by frame pieces as 34 so that they are vibrated together. Thedetails of the frames are not illustrated.

The front edge of the screed 3| is extended upwardly into a hopper wall35 while the screed or shoe' 33 is extended upwardly into a hopper wall36, these walls diverging upwardly and being spaced at 31 to provide adischarge throat for the hopper, the screeds being curved upwardly tothis throat, as illustrated, so that the grout is allowed to spreadabove the aggregate at a point below this throat. This allows thegrouting to flow forwardly and spread much more effectively than wouldbe the case if the restricted point of the throat were immediately abovethe aggregate.

The shoe or screed 33 serves to flatten out the aggregate and, to aconsiderable degree, vibrate it as results from the forward screed inthe em-- bodiment shown in Figs. 1 to 3. By maintaining the grout undera substantial constant head, it is very uniformly discharged and bydischarging it into the confined space ahead of the vibrating screed,the grout is prevented from spreading too rapidly under the screeds witha result that deeper penetration in the aggregate is had. The vibratingof the forward shoe results in substantial penetration of the groutingbefore acted upon directly by the rear screed which results in furtherpenetration. To eliminate backing up the device as might be requiredunder certain conditions, that is, to insure grouting with one passageover the aggregate, I provide the second unit which has the furtheradvantage of thorough grouting at a higher rate of travel of theapparatus.

In the embodiment of my invention illustrated in Fig. 6, the mixer 26 ismounted upon the carriage 38 of a paving machine of a type shown invoids in the rock due to its own gravity flow.

my copending' application having a screed 39 mounted for reciprocatingmovement transversely of the path of travel of the screed, the screedsupports 40 permitting such movement. The reciprocating means are nothere illustrated. The vibrating unit is indicated at 4| and ispreferably that of my said application. This screed 39 has a curved nose42 with a hopper wall 43 extending upwardly therefrom. A curved shoe 44corresponding to the shoe 33 is provided, this shoe having a hopper wall45 extending upwardly therefrom. The shoe 44 is connected to the vibrating and reciprocating screed by means of the frame pieces 46 so thatthe hopper is vibrated as a whole and also reciprocated. Thereciprocation of the screed results in a more efficient troweling andsmoothing action than is had with the embodiment of my invention shownin Figs. 1 to inclusive; otherwise, the machine functions substantiallythe same as the embodiment of my invention shown in Fig. 5.

All three forms or embodiments of my invention are highly eflicient,enabling the use of grouting of low water content, and at the same timesecuring effective penetration with the aggregate with such groutingwhich notonly results in reducing costs, but results in a concrete ofvery great strength and uniformity.

It is to be understood that by non-flowing water content, I contemplategrouting of such lower water content that it will not flow or penetratethe aggregate by gravity, although it should also be borne in mind thatby vibratingthe grouting in the hopper, its fluidity is greatlyincreased and I am able to successfully place grouting of a much lowerWater content than would be possible merely by applying the grouting andsubjecting to a vibrating screed.

I have not attempted to illustrate and describe other embodiments of myinvention or other forms of apparatus for the practice of my method asit is believed that this disclosure will enable those skilled in the artto embody or adapt my invention as may be desired. The machineillustrated I has been found highly practical.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent, is:

1. In a structure'of the class described, the combination of front andrear screeds disposed in spaced parallel relation and comprising shoeshaving rounded noses, the front screed having a rounded heel portionextended into a forwardly inclined hopper wall, the rounded nose of therear screed being extended into a rearwardly inclined hopperwall, saidrounded heel and nose coacting to provide a downwardly expanding hopperdischarge throat, a discharge valve adjustably supported centrally abovesaid hopper discharge throat and in coacting relation thereto, andelectric motors provided with unbalancing weights mounted on saidscreeds.

2. In an apparatus for laying cement bonded macadam, the combination ofa pair of screed members disposed in spaced parallel relation andcomprising shoes having rounded inner edges, said edges of the shoesbeing extended into upwardly diverging hopper walls, the rounded inneredges being spaced to provide a hopper discharge, a discharge gateadjustably supported centrally above said hopper discharge, and electricmotors provided with unbalancing weights mounted on the shoes of bothscreeds, one of the screeds being provided with a propelling means.

3. In a structure of the class described, the

comprising fiat-bottomed shoes having *rounded outer and inner edges,the rounded inner edges of the shoes being extended into upwardlydiverging hopper walls, the rounded inner edges being spaced to providea hopper discharge, and means for vibrating said screeds while they arebeing propelled across a bed of aggregate.

5. In a structure of the class described, the combination of front andrear screeds disposed in spaced parallel relation and comprising shoes,the rear edge of the front screed being extended into a forwardlyinclined hopper wall, the front edge of the rear screed being extendedinto a rearwardly inclined hopper wall, the walls being spaced at thebottom to provide an elongated discharge between the screeds, adischarge gate adjustably supported centrally above said discharge andin coacting relation thereto, and motors having rotors provided withunbalancing weights mounted on said screeds.

6. In an apparatus for laying cement bonded macadam, the combination ofa pair of screed members disposed in spaced parallel relation andcomprising shoes, the adjacent edges of the shoes being extendedupwardly to provide diverging hopper walls spaced at the bottom toprovide elongated hopper discharge between the screeds, a discharge gateadjustably supported centrally above said discharge, and motors havingrotors provided with unbalancing weights mounted on both screeds, one ofthe screeds being provided with a propelling means.

7. In a machine for working cement grout into macadam aggregate, thecombination of screeds arranged in trailing relation and havingcooperating hopper walls providing a hopper discharging between thescreeds, and means for vibrating the screeds at high frequency whilethey are being propelled across a bed of aggregate, said hopper wallsbeing vibrated with the screeds.

8. In a machine for grouting aggregate in situ, the combination ofscreeds disposed in trailing relation to be translated together across abed of aggregate, means for vibrating the screeds at high frequencywhile traveling, means for discharging cement grout at the rear of thefront screed and in advance of the trailing screed, the discharge meansincluding a hopper the walls of which are vibrated with said screeds,and an adjustable discharge gate.

9; In a machine for working cement grout into macadarn aggregate, thecombination of screeds arranged in trailing relation, a hopperdischarging between the screeds, and means for vibrating the screeds athigh frequency while they are being propelled across a bed of aggregate,said hopper being vibrated with the screeds.

10. In a machine for grouting aggregate in situ, the combination ofscreeds disposed in trailing relation to be translated together as aunit across a bed of aggregate, means for vibrating the screeds at highfrequency while traveling, and means for isflchtrgitgr cement loutattherear of the stat screed nd in sashes-tithe trailing screed. i 11-; I n*amachine of the class described a'unit "c'omprisi'ng' screeds arranged intrailing relation,

a hopper dischargingbetwee n the screeds, and means for vibratingthescreeds at high frequency while they are traveling, saidhopper wallsbeing vibrated with the screeds. i

12 In a machine'of the 'class described, the

combinationof screeds disposed in trailing relation tojbe propelledtogetherimeans'for vibrating the'screeds at high frequency whiletraveling, and means for discharging material at the rear of the frontscreed and in advance of the trailing screed, the discharge meansincluding a hopper the walls of which are vibrated with said screeds.

13. In' a machine of the "class described, the

combination of screeds arranged intrailing relation, and having shoesthe bottoms of which are flat and are disposed in the same horizontalplane, a hopper discharging between the screeds, and means for vibratingthe screeds at high frequency while they are traveling as a unit.

14. In a machine of the class described, a unit comprising screedsdisposed in trailing relation to be propelled together, means forvibrating the screeds at high frequency while traveling, and means fordischarging material at the rear of the front screed and in advance ofthe trailing screed.

15. In a structure of the class described, the combination of front andrear screeds disposed in spaced parallel relation and provided withdownwardly converging hopper walls spaced at their lower edges toprovide a narrow discharge, the adjacent parts of screeds being curvedupwardly and merging into said hopper walls, and means for vibratingsaid screeds and the hopper walls at high frequency.

16. In a structure of the class described, a unit spaced parallelrelation and provided with downwardly converging hopper walls spaced attheir lower edges to provide a discharge, and means for vibrating saidscreeds and the hopper walls at high frequency.

17. In a machine of the class described, the combination of a pair ofscreeds mounted for reciprocatory movement as they are advanced, theadjacent portions of the screeds being extended into upwardly diverginghopper walls providing a hopper reciprocating with the screeds, andmeans for vibrating the screeds and hopper at high frequency as they areadvanced and reciprocated, and means for discharging grout to the hopperas the machine is advanced to maintain a substantially uniform head ofgrout.

18. In a machine of the class described, the combination of a pair ofscreeds mounted for reciprocatorymovement as they are advanced, theadjacent portions of the screeds being extended into upwardly diverginghopper walls providing a hopper reciprocating with the screeds, andmeans for vibr'ating the screeds and hopper at high frequency as theyare advanced and reciprocated.

19. In a machine of the class described, the combination of a screedmounted for reciprocatory movement as it is advanced, a hopper retorymovement as it is advanced, a hopper reciprocating with the screed anddischarging at the front thereof, and means for vibrating the screed andhopper at high frequency as they are advanced and reciprocated as aunit.

21. In a machine of the class described, the combination of a pair ofscreeds adapted for reciprocatory movement as they are advanced as aunit, a hopper discharging between the screeds, means for vibrating thescreeds and hopper at high frequency as they are advanced, and means fordelivering material to the hopper as the machine is advanced formaintaining a substantial- 1y uniform head therein.

22. In a machine of the class described, the combination of a pair ofscreeds adapted for reciprocatory movement as they are advanced as aunit, a hopper discharging between the screeds, and means for vibratingthe screeds and hopper at high frequency as they are advanced.

23. In a paving machine, the combination of screed means adapted to restdirectly upon the material to be worked and support the paving machinethereon, a hopper operatively associated with said screed means, andmeans acting to rapidly vibrate the paving machine at high frequency tofacilitate the operation of said hopper and screed means and to vibratethe material supporting the paving machine to condition the samethroughout its mass before, during and after the delivery of materialthereto by said hopper.

CORWILL JACKSON.

